Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.

IOSECT

Prolog  

Control Block Contents  
   IOSECT DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


IOSECT Prolog

 Name       : IOSECT
 Description: I/O Interrupt Save Area
 DSECT      : IOSECT
 Function   : IOSECT describes the fields used by DMSITI for
              saving registers, the I/O old PSW, and other
              data when handling I/O interrupts. IOSECT is
              pointed to by the AIOSECT field in NUCON.
              IOSECT is mapped by the IOSECT macro.

 

IOSECT Control Block Content


IOSECT DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      IOSECT         I/O Interrupt Save Area
0000    0 Signed       4 IOSAVE (16)    Register save area
0040   64 Signed       4 IONTABL        Size of user interrupt table in
                                        bytes
0044   68 Address      4 AUSRITBL       Address of user interrupt table
0048   72 Signed       4 *              Length of each entry
004C   76 Address      4 AUSRILST       Address of last entry in table
0050   80 Signed       4 OLDEST (4)     Oldest I/O old PSW and CSW
0060   96 Signed       4 NEXTO (4)      Next oldest I/O old PSW and CSW
0070  112 Signed       4 IOPSW (2)      Newest I/O old PSW
0078  120 Signed       4 IOCSW (2)      Newest CSW
       INTBLOK build area
0080  128 Bitstring    1 IOSINTBK (0)   Start of INTBLOK build area
0080  128 Bitstring    8 IOSIINFO (0)   Interrupt information
0080  128 Signed       4 IOSIPARM       For XA/XC, interruption
                                        parameter; for 370, 0
0084  132 Bitstring    4 IOSIIDNT (0)   For XA/XC, subsystem ID word
                                        (SID); for 370, see individual
                                        components
0084  132 Signed       2 *              For XA/XC, X'0001'; for 370, 0
0086  134 Signed       2 IOSISBDV       For XA/XC, subchannel number; for
                                        370, device address
0088  136 Bitstring    8 IOSIBPSW       I/O old PSW
0090  144 Bitstring   64 IOSIBIRB (0)   For XA/XC, actual interruption
                                        response block (IRB); for 370,
                                        constructed IRB
0090  144 Bitstring   12 IOSIBCSW (0)   For XA/XC, actual subchannel
                                        status word (SCSW); for 370,
                                        constructed SCSW
0090  144 Bitstring    1 IOSIKSLC       Key, S, L, and CC
0091  145 Bitstring    1 *              FOR XA/XC, MISCELLANEOUS SCSW
                                        BITS; FOR 370, 0
          1... ....      IOSICCWF       X'80' For XA/XC, CCW format; for
                                        370, 0
0092  146 Bitstring    2 *              For XA/XC, more miscellaneous
                                        SCSW bits; for 370, 0
0094  148 Address      4 IOSIBCCW       For XA/XC, CCW address; for 370,
                                        X'00' and 3-byte CCW address
0098  152 Bitstring    1 IOSIDVST       Device status
0099  153 Bitstring    1 IOSISCST       For XA/XC, subchannel status; for
                                        370, channel status
009A  154 Signed       2 IOSIRCNT       Residual byte count
009C  156 Signed       4 * (13)         For XA/XC, extended status word
                                        (ESW) and extended control word
                                        (ECW); for 370, 0
00D0  208 Bitstring    1 IOSISTAT       Status of INTBLOK information
          1... ....      IOSIFAIL       X'80' IOSIFAIL For XA/XC, if 1,
                                        TSCH failed and IRB is not valid;
                                        for 370, always 0
          .1.. ....      IOSIPSEU       X'40' IOSIPSEU For XA/XC, always
                                        0 (actual information given); for
                                        370, always 1 (constructed, or
                                        "pseudo", information given)
00D1  209 Bitstring    1 *              Reserved
00D2  210 Signed       2 IOSDEVNM       Save device addr for user exit
          00000054       IOSIBLEN       *-IOSINTBK Length of INTBLOK
                                        build area
00D4  212 Bitstring   40 IOSDVBLD       Build area for candidate entry
00FC  252 Signed       4 IOSEPSW (2)    I/O old PSW for PSW reg setup
0104  260 Signed       4 HOLD           Holds entry pointer for device
0108  264 Signed       2 VSTRANGE       Unknown device address
010A  266 Bitstring    1 IOSTFLAG       I/O status flag
          1... ....      IOSAMSAV       X'80' IOSAMSAV SLIH invoked with
                                        AMODE=31
          .1.. ....      IOSHDEDH       X'40' IOSHDEDH DMSHDEDH is active
          ..1. ....      IOSABN         X'20' IOSABN DMSABN is active
          ...1 ....      IOSUIO         X'10' IOSUIO I/O user routine
010B  267 Bitstring    1 *              RESERVED FOR FUTURE USE
010C  268 Address      4 IOSWAITE       Address of waiting routine to be
                                        invoked after WAITD is issued
0110  272 Signed       4 IOSBASE        DMSITI's base register
0114  276 Signed       4 IOSAVE2 (24)   Save area used by routines called
                                        from DMSITI
0174  372 Bitstring   64 IOAREGS        Save area for access registers in
                                        XC machine
01B4  436 Signed       4 IOSC14SV       Save area for control reg 14
01B8  440 Signed       4 IOSC14WK       Work area for control reg 14
01C0  448 Dbl-Word     8 *              Reserved for future use

 

IOSECT Storage Layout

          
*** IOSECT - I/O Interrupt Save Area
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                        IOSAVE                         =
*     |                                                       |
*     +---------------------------+---------------------------+
*  40 |         IONTABL           |         AUSRITBL          |
*     +---------------------------+---------------------------+
*  48 |///////////////////////////|         AUSRILST          |
*     +---------------------------+---------------------------+
*  50 |                        OLDEST                         |
*     |                                                       |
*     +-------------------------------------------------------+
*  60 |                        NEXTO                          |
*     |                                                       |
*     +-------------------------------------------------------+
*  70 |                        IOPSW                          |
*     +-------------------------------------------------------+
*  78 |                        IOCSW                          |
*     +---------------------------+-------------+-------------+
*  80 |         IOSIPARM          |/////////////|  IOSISBDV   |
*     +---------------------------+-------------+-------------+
*  88 |                       IOSIBPSW                        |
*     +------+------+-------------+---------------------------+
*  90 |:IKSLC|//////|/////////////|         IOSIBCCW          |
*     +------+------+-------------+---------------------------+
*  98 |:IDVST|:ISCST|  IOSIRCNT   |///////////////////////////|
*     +------+------+-------------+///////////////////////////|
*  A0 |///////////////////////////////////////////////////////|
*     =///////////////////////////////////////////////////////=
*     |///////////////////////////////////////////////////////|
*     +------+------+-------------+---------------------------+
*  D0 |:ISTAT|//////|  IOSDEVNM   |                           |
*     +------+------+-------------+                           |
*  D8 |                                                       |
*     =                       IOSDVBLD                        =
*     |                           +---------------------------+
*     |                           |         IOSEPSW-          |
*     +---------------------------+---------------------------+
* 100 |          -(0FC)           |           HOLD            |
*     +-------------+------+------+---------------------------+
* 108 |  VSTRANGE   |:TFLAG|//////|         IOSWAITE          |
*     +-------------+------+------+---------------------------+
* 110 |         IOSBASE           |                           |
*     +---------------------------+                           |
* 118 |                                                       |
*     =                       IOSAVE2                         =
*     |                           +---------------------------+
*     |                           |                           |
*     +---------------------------+                           |
* 178 |                                                       |
*     =                       IOAREGS                         =
*     |                           +---------------------------+
* 1B0 |                           |         IOSC14SV          |
*     +---------------------------+---------------------------+
* 1B8 |         IOSC14WK          |///////////////////////////|
*     +---------------------------+---------------------------+
* 1C0 |///////////////////////////////////////////////////////|
*     +-------------------------------------------------------+
* 1C8
*
*** IOSECT - I/O Interrupt Save Area

 

IOSECT Cross Reference

Symbol         Dspl Value
-------------- ---- -----
AUSRILST       004C
AUSRITBL       0044
HOLD           0104
IOAREGS        0174
IOCSW          0078
IONTABL        0040
IOPSW          0070
IOSABN         010A 20
IOSAMSAV       010A 80
IOSAVE         0000
IOSAVE2        0114
IOSBASE        0110
IOSC14SV       01B4
IOSC14WK       01B8
IOSDEVNM       00D2
IOSDVBLD       00D4
IOSEPSW        00FC
IOSHDEDH       010A 40
IOSIBCCW       0094
IOSIBCSW       0090
IOSIBIRB       0090
IOSIBLEN       00D2 00000054
IOSIBPSW       0088
IOSICCWF       0091 80
IOSIDVST       0098
IOSIFAIL       00D0 80
IOSIIDNT       0084
IOSIINFO       0080
IOSIKSLC       0090
IOSINTBK       0080
IOSIPARM       0080
IOSIPSEU       00D0 40
IOSIRCNT       009A
IOSISBDV       0086
IOSISCST       0099
IOSISTAT       00D0
IOSTFLAG       010A
IOSUIO         010A 10
IOSWAITE       010C
NEXTO          0060
OLDEST         0050
VSTRANGE       0108

This information is based on z/VM V6R1.0.
Last updated on 23 Oct 2009 at 11:01:42 EDT.
Copyright IBM Corporation, 1990, 2008